Which of the most widely used OO metrics cannot be used for Scala?
Which of the most widely used OO metrics cannot be used for Scala ? Why ? Which one of them you do not expect to work the same way in Scala as they do in Java or C++ ? Which one are safe to use in Scala ?
See common Java metrics at http://agile.csc.ncsu.edu/SEMaterials/OOMetrics.htm
I would think that coupling, encapsulation or cohesion related metrics, for example, would be just fine for Scala, this is however just an educated guess, so it would be interesting to hear developers' opinions who have real field experience in using OO metrics for Scala.
Most of them are valid, but you may find that the actual numbers vary wildly.
Cyclomatic complexity, for example, should be significantly lower when writing in a functional style.
coupling/inheritance is possibly going to be higher, depending on how it's measured. The cake pattern definitely drives up the amount of inheritance.
implicits will doubtless drive up some numbers as well, and there are no metrics I know of that specifically recognise type classes or the loose-coupling nature of implicits.
You're also going to see much lower metrics for the amount of hidden methods/attributes, driven in large part by the use of immutable objects.
So yes... you can take most of the measurements. I'm just not sure if you can interpret them in any meaningful way.